Effects of Echo-optimization of Left Ventricular Assist Devices on Functional Capacity (VAFRACT)

The use of Left Ventricular Assist Devices (LVAD) is a viable therapeutic option to improve survival and quality of life of patients with advanced and refractory heart failure (HF). However, after the implantation of an LVAD, patients' functional capacity (FC) is still reduced with maximum oxygen uptake (VO2 peak) values calculated at the cardiopulmonary exercise test (CPET) ranging from 11 to 20 ml/kg/min. LVAD echo guided optimization (EO) determines a more favorable hemodynamic profile, in particular for the right ventricle, and could provide an improvement on FC. VAFRACT is a prospective randomized trial to evaluate the additional benefit of an EO approach on FC, measured by CPET in LVAD optimization free population.

The optimal device speed is defined as the one that allows an intermittent aortic valve opening and a neutral position of the interventricular septum without increasing aortic or tricuspid regurgitation associated or not to a dilatation of the right ventricle (RV). In this condition it is reasonable to expect a more favorable hemodynamic profile for the RV and a better response in terms of functional capacity.

Subjects studied are HF patients supported with a continuous-flow LVAD: HeartMate II (Thoratec Inc., Pleasanton, CA) and HeartMate 3 (HM 3, Abbott, North Chicago, IL). Patients are recruited from our Day Hospital of the Cardiac Surgery Department at the University Hospital of Verona.

Inclusion criteria

• at least 3 months after LVAD implantation;
• compliance to the required follow-up schedule;
• age 18 or above or of legal age to give informed consent specific to state and national laws.

Exclusion criteria

• distance of less than 150 meters on the six-minute walk test (6MWT) or impossibility to perform CPET
• recent finding of any major device-related complication (sepsis, thrombosis …).